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Re: Pentium-M



On Tue, 2003-11-04 at 03:05, Martin Wegmann wrote:
> Hello,
> 
> [snip]
> > I think something has to be wrong... 1 1/2h battery life using a Centrino
> > based laptop?  8-?
> >
> > Mine's an Acer TM290, and the battery lasts about 4h under linux (never
> > tryed that under windows).  Of course it depends on your use of it but...
> >
> > Are you using cpufreq?  Is your laptop running at a lower speed when on
> > battery (cat /proc/cpuinfo)?  8-?
> 
> I am using a T 40 (Pent. M as well), it lasts about 3 h with kde3.1 but I 
> would be keen to extend the battery life when running on battery only or on 
> low battery.
> 
> my cpu MHz value is the same when runnign on battery or not - how do I 
> activate cpufreq that? It is a program or a function?

It is a kernel option. On kernel 2.4 you need a kernel patch. Under 2.6
its built in.
Another thing that may interest you is laptopmode (built in on kernel
2.4.23-pre7+, maybe 2.4.23-pre6). It delays disk writes so that your
disk has a chance to spin down. You risk loosing some data in the event
of a crash, but you can extend the battery life by 5%-10% probably
(maybe more). It does have a problem with journaled file systems though
as they bypass the kernel's dirty buffer for the journal writes. I made
a patch to fix reiserfs if you want.
You should use a script from acpid or something like that to activate it
and cpufreq. I can send it to you if you want (you will still need the
features enabled in the kernel).
I am getting almost 4h on a sony vaio pcg-fxa53 (amd athelon 1.3GH) with
these (If I am not stressing the computer in which case it can drop
bellow 2h).

> 
> cat /proc/cpuinfo
> processor       : 0
> vendor_id       : GenuineIntel
> cpu family      : 6
> model           : 9
> model name      : Intel(R) Pentium(R) M processor 1300MHz
> stepping        : 5
> cpu MHz         : 1298.912
> cache size      : 0 KB
> fdiv_bug        : no
> hlt_bug         : no
> f00f_bug        : no
> coma_bug        : no
> fpu             : yes
> fpu_exception   : yes
> cpuid level     : 2
> wp              : yes
> flags           : fpu vme de pse tsc msr mce cx8 apic sep mtrr pge mca cmov 
> pat clflush dts acpi mmx fxsr sse sse2 tm
> bogomips        : 2595.22
> 
> 
> cheers Martin
> -- 
> -----
> please send me a CC when replying
-- 
Micha Feigin
michf@math.tau.ac.il



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